1. Field of the Invention
The present invention is related to a sheet stacking device for forming a stack of subsequent sheets and to a printing system comprising such a sheet stacking device.
2. Description of Background Art
A typical example of such a sheet stacking device is known from U.S. Pat. No. 5,065,997. This known device comprises a pair of disks, which have been mounted onto a driven rotation shaft. Each one of the disks comprises a pair of acceptance slots, as well as a pair of friction elements. During the course of a cycle, incoming sheets may be accepted into the slots that have been made in the disk. If applicable, the incoming sheets have already sustained an initial lateral registration course and are conveyed into a slot by means of an input clamping arrangement. An accepted sheet is conveyed onto a receiving plane during part of the revolution, after which the friction elements will convey the sheet against a stop during part of the revolution.
A disadvantage of this known device is that, in use, it is not sufficiently precise in producing accurately formed stacks. In use, it regularly happens that sheets stacked by the known device fail to end up in an orderly manner on the stack formed on the receiving plane. Deviations in the orientation of sheets relative to one another and relative to the reference planes are highly undesirable, particularly if the stacks are to be further post-processed, such as in binding applications.